The Firing Line Forums - View Single Post - .44 cal Colt Army to .45; Does it Really Work?

Driftwood Johnson · February 24, 2018, 10:40 AM

Howdy

I have been shooting 45 Colt Black Powder ammo through conversion cylinders in '44' caliber C&B revolvers for years.

1. A caliper, particularly a cheap one is the wrong tool for measuring rifling groove diameter. The inside measuring points usually have a flat on them, which introduces an error. Even with expensive calipers. Inexpensive calipers will only make it worse.

2. As was stated, it is difficult to measure rifling, even when slugging the barrel, when there are an odd number of grooves. About the best you can do with a slug from a barrel with an odd number of grooves is measure from land to groove on the slug, then use the extension portion of the caliber to measure the height of the land on the slug, and add that to the groove to land diameter. A difficult task at best.

Standard groove diameter for 45 Colt today is .451. When I first started fooling around with conversion cylinders I slugged the barrel of my old EuroArms Remmie. It turns out the groove diameter was about .449. A little bit tight for 45 Colt, but with soft lead bullets it created no problems.

When Colt 44 caliber C&B revolvers were first modified to shoot cartridges, the 44 Colt cartridge was developed. The 44 Colt round was sized to fit the 44 caliber chambers. Of course, the rear end of the cylinders where the nipples were located was cut away. A heeled bullet of about .451 was used because that fit the rifling grooves of the C&B revolvers.

Here is a photo of some old cartridges. Left to right they are 44-40, 44 Henry Rimfire, 44 S&W American, 44 Russian, 44 Colt, 44 Special, and 45 Colt.

This is a Richards Conversion of the 1860 Army Colt, with a few of the 44 Colt cartridges developed for it.

February 24, 2018, 10:40 AM	#15
Driftwood Johnson Senior Member Join Date: January 3, 2014 Location: Land of the Pilgrims Posts: 2,033	Howdy I have been shooting 45 Colt Black Powder ammo through conversion cylinders in '44' caliber C&B revolvers for years. 1. A caliper, particularly a cheap one is the wrong tool for measuring rifling groove diameter. The inside measuring points usually have a flat on them, which introduces an error. Even with expensive calipers. Inexpensive calipers will only make it worse. 2. As was stated, it is difficult to measure rifling, even when slugging the barrel, when there are an odd number of grooves. About the best you can do with a slug from a barrel with an odd number of grooves is measure from land to groove on the slug, then use the extension portion of the caliber to measure the height of the land on the slug, and add that to the groove to land diameter. A difficult task at best. Standard groove diameter for 45 Colt today is .451. When I first started fooling around with conversion cylinders I slugged the barrel of my old EuroArms Remmie. It turns out the groove diameter was about .449. A little bit tight for 45 Colt, but with soft lead bullets it created no problems. When Colt 44 caliber C&B revolvers were first modified to shoot cartridges, the 44 Colt cartridge was developed. The 44 Colt round was sized to fit the 44 caliber chambers. Of course, the rear end of the cylinders where the nipples were located was cut away. A heeled bullet of about .451 was used because that fit the rifling grooves of the C&B revolvers. Here is a photo of some old cartridges. Left to right they are 44-40, 44 Henry Rimfire, 44 S&W American, 44 Russian, 44 Colt, 44 Special, and 45 Colt. This is a Richards Conversion of the 1860 Army Colt, with a few of the 44 Colt cartridges developed for it. Last edited by Driftwood Johnson; February 24, 2018 at 10:49 AM.